function blockgame.reg_simple_node (name, desc, groups)
	local my_modname = minetest.get_current_modname()
	return blockgame.register_node(my_modname .. ":" .. name, {
		description = desc,
		tiles = {
			my_modname .. "_" .. name .. ".png",
		},
		groups = groups,
	})
end



-- probably temporary; will probably use groups for this later.
local air_flowable = {
	"air",
	"bg_tree:leaves",
	"bg_tree:leaves_alive",
}

function blockgame.air_flows_through (pos, node)
	node = node or minetest.get_node(pos)
	local node_name = node.name
	for _, name in pairs(air_flowable) do
		if name == node_name then return true end
	end
	return false
end



function blockgame.attempt_place (pos, node)
	if minetest.get_node(pos).name ~= "air" then return false end
	minetest.set_node(pos, node)
	return true
end



function blockgame.random_walk (data)
	local pos = vector.copy(data.pos)
	local min_steps = data.min_steps or 0
	local max_steps = data.max_steps or 8
	local check = data.check
	local neighborhood = data.neighborhood or blockgame.vector.dirs

	local steps = math.random(min_steps, max_steps)
	local step = 0

	while step < steps do
		local dir = blockgame.random_element(neighborhood)
		local new_pos = pos + dir
		if check(new_pos, minetest.get_node(new_pos)) then pos = new_pos end
		step = step + 1
	end
	return pos
end